Prostate cancer (PCa) incidence and mortality in African American men is two times greater than men of other races/ethnicities in the United States. Elucidating the underlying mechanisms for this cancer health disparity (CHD) is critical to patient treatment and improved patient outcome, however there are no in vitro models available to adequately recapitulate the PCa tumor microenvironment across races/ethnicities. In Phase I we aimed to address this need by optimizing culture conditions of a 3D in vitro model system, the PCa OncoPlate. We developed four PDX-derived PCa models of varied racial/ethnic backgrounds with stromal fibroblasts and endothelial blood vessel mimics under continuous perfusion. Viable for at least 7 days, cultures maintained phenotypic PCa features and responded to chemotherapies. This study will establish 50 PCa PDX models (African American, Caucasian, Hispanic, Asian) and optimize 3D culture conditions in the OncoPlate along with stromal, endothelial, and immune cells. PCa behavior including cell proliferation and response to chemotherapies will be evaluated. Once executed these studies will establish the PCa OncoPlate as a high throughput screening platform for use by pharmaceutical companies and academic laboratories to investigate the CHD and ultimately select the appropriate therapeutics for African American men suffering from PCa.